Understanding and Using Context
Summary (2 min read)
1. Introduction
- Humans are quite successful at conveying ideas to each other and reacting appropriately.
- This is due to many factors: the richness of the language they share, the common understanding of how the world works, and an implicit understanding of everyday situations.
- Unfortunately, this abili ty to convey ideas does not transfer well to humans interacting with computers.
- Finally, architectural support wil l enable designers to build their applications more easily.
- The authors wil l review previous attempts to define and provide a characterization of context and context-aware computing, and then present their own definition and characterization.
2. What is Context
- To develop a specific definition that can be used prescriptively in the contextaware computing field, the authors wil l look at how researchers have attempted to define context in their own work.
- While most people tacitly understand what context is, they find it hard to elucidate.
2.1 Previous Definitions of Context
- In the work that first introduces the term ‘context-aware,’ Schili t and Theimer [7] refer to context as location, identities of nearby people and objects, and changes to those objects.
- These types of definitions that define context by example are diff icult to apply.
- The definitions by Schil it et al. [6] and Pascoe [3] are closest in spirit to the operational definition the authors desire.
- The authors cannot enumerate which aspects of all situations are important, as this will change from situation to situation.
- For this reason, the authors could not use these definitions provided.
2.2 Our Definition of Context
- An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves.
- This definition makes it easier for an application developer to enumerate the context for a given application scenario.
- The obvious entities in this example are the user, the application and the tour sites.
- The weather does not affect the application because it is being used indoors.
- Therefore, the presence of other people is context because it can be used to characterize the user’s situation.
3. Defining Context-Aware Computing
- Context-aware computing was first discussed by Schil it and Theimer [7] in 1994 to be software that “adapts according to its location of use, the collection of nearby people and objects, as well as changes to those objects over time.”.
- Since then, there have been numerous attempts to define context-aware computing, most of which have been too specific [2].
3.2 Features for Context-Aware Applications
- Similar to the problem of defining context-aware, researchers have also tried to specify the important features of a context-aware application [3,6].
- Again, these features have tended to be too specific to particular applications.
- The proposed categorization combines the ideas from previous taxonomies and attempts to generalize them to satisfy all existing context-aware applications.
4. Support for Building Applications
- With an understanding of what context is and the different ways in which it can be used, application builders can more easily determine what behaviors or features they want their applications to support and what context is required to achieve these behaviors.
- Application builders may need help moving from the design to an actual implementation.
- The first is a combination of architectural services or features that designers can use to build their applications from.
- The second form is abstractions that allow designers to think about their applications from a higher level.
- The authors have built an architecture, the Context Toolkit, that contains a combination of features and abstractions to support context-aware application builders.
4.1 Features for Context-Aware Applications
- The Context Toolkit makes it easy to add the use of context to existing noncontext-aware applications and to evolve existing context-aware applications.
- In contrast, their context-aware applications do not instantiate individual context widgets, but must be able to access existing ones, when they require.
- The sensors must be physically distributed and cannot all be directly connected to a single machine.
- The Context Toolkit makes the distribution of the context architecture transparent to context-aware applications, mediating all communications between applications and components.
- This abstraction, a context aggregator, is responsible for all the context for a single entity.
Did you find this useful? Give us your feedback
Citations
1,310 citations
Cites background from "Understanding and Using Context"
...In the literature several definitions of the term context can be found [36, 35, 32, 37, 10, 16 , 41]....
[...]
1,201 citations
Cites background or methods from "Understanding and Using Context"
...In context-aware computing, most approaches for manual situation specification refer to Dey’s context definition [15] as ‘‘any information that can be used to characterise the situation of an entity’’....
[...]
...Situational context [45] and situation [15,46] are the most common ones....
[...]
...[15], space can be seen as a central aspect of context entities: ‘‘An entity is a person, place or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves’’—places are spatial entities, and interaction typically requires some vicinity....
[...]
1,001 citations
Cites background from "Understanding and Using Context"
...It specifies any information that can be used to characterize the background or situation of the involved entities [5]....
[...]
...Dey defined the ability of a computing system to identify and adapt to its context as context-awareness [5]....
[...]
931 citations
Additional excerpts
...(3,1) (4,1) (5,1) (0,1) (1,1) (2,1) (6,1) (7,1) (8,1) (9,1)...
[...]
...(3,2) (4,2) (5,2) (0,2) (1,2) (2,2) (6,2) (7,2) (8,2) (9,2)...
[...]
795 citations
References
4,842 citations
"Understanding and Using Context" refers background in this paper
...Since then, there have been numerous attempts to define context-aware computing, most of which have been too specific [ 7 ]....
[...]
3,802 citations
"Understanding and Using Context" refers background in this paper
...In previous work, we presented the context widget [5], an abstraction that implements this concept....
[...]
1,787 citations
"Understanding and Using Context" refers background in this paper
...Other definitions have simply provided synonyms for context; for example, referring to context as the environment or situation [1,4,8]....
[...]
1,606 citations
"Understanding and Using Context" refers background in this paper
...Other definitions have simply provided synonyms for context; for example, referring to context as the environment or situation [1,4,8]....
[...]
1,337 citations
"Understanding and Using Context" refers background in this paper
...referring to context as the environment or situation [1,4, 8 ]....
[...]
Related Papers (5)
Frequently Asked Questions (7)
Q2. What is the purpose of the Context Toolkit?
The Context Toolkit makes it easy to add the use of context to existing noncontext-aware applications and to evolve existing context-aware applications.
Q3. What is the purpose of the architecture?
Their architecture is built on the concept of enabling applications to obtain the context they require without them having to worry about how the context was sensed.
Q4. What is the purpose of the context toolkit?
The Context Toolkit makes the distribution of the context architecture transparent to context-aware applications, mediating all communications between applications and components.
Q5. What are the three categories of features that a context-aware application can support?
There are three categories of features that a context-aware application can support:• presentation of information and services to a user; • automatic execution of a service for a user; and • tagging of context to information to support later retrievalWith an understanding of what context is and the different ways in which it can be used, application builders can more easily determine what behaviors or features they want their applications to support and what context is required to achieve these behaviors.
Q6. What was the definition of context-aware computing?
Context-aware computing was first discussed by Schilit and Theimer [7] in 1994 to be software that “adapts according to its location of use, the collection of nearby people and objects, as well as changes to those objects over time.”
Q7. What is the role of the context toolkit?
Instead,the Context Toolkit is responsible for the translation of the description to the “wiring” of the context components and for determining when the individual elements of the situation have been collectively satisfied.